AUDIE CORNISH, HOST:
The fires now raging in Colorado and elsewhere may be bad, but scientists studying the relationship between wildfires and climate change have this warning: In the coming years, they're probably going to get worse.
Max Moritz is lead author of the study and on the faculty at the University of California, Berkeley's College of Natural Resources.
And, Max, what you did here is try to predict where in the future fires are likely to occur and how frequently. How did you do that and what did you find?
MAX MORITZ: Well, we used a family of techniques that's been developed for looking at range shifts for different organisms, actually under climate change, and we applied it to fire.
CORNISH: So, range shifts meaning models tracking how animals move across a certain area?
MORITZ: Pretty much. Basically, animals have different environmental requirements for their habitat. And it turns out that fire has similar sets of requirements for where it can exist. So you basically quantify the relationships between where you see different frequencies of observations and what the environmental characteristics - climatic characteristics in this case - are. You quantify those relationships and then you project them forward using global climate projections.
CORNISH: So, you studied trends all over the world. Where will be the hotspots, so to speak, when it comes to future wildfires?
MORITZ: Well, as you look in the near term, so for the next, say, 30 years or so, there's pretty decent model agreement because we used a whole bunch of different global climate projections. We don't just use one - that's kind of one of the unique things about this study. We use 16 different projections. And as you project those into the future, you do see that about half the planet in the next 30 years shows pretty big disruptions, mostly increases in fire and those are mostly seen in different parts of the Northern Hemisphere.
Much of the western U.S., in particular, shows strong agreement for the largest increases. Overall it's a more fire-prone situation across much of the western U.S.
CORNISH: Now, how and why do you connect this to climate change?
MORITZ: Well, we know that climate controls a certain set of factors that drive fire. So basically fire is controlled by rates of vegetation growth, on one hand - you have to have something to burn - and climate has a strong effect on that. And then, on the other hand, climate has a strong effect on flammability; how dry during the warm dry season, if there is one, how dry does that vegetation get. And those are both factors that affect fire and they're both driven by climatic variables.
CORNISH: Now, you said that in the future that we'll have to rethink how we live with fire. Now, what did you mean by that, in what ways? 'Cause I know that there's precautions people do take right now when it comes to dealing with wildfires.
MORITZ: Right, well, so we know when we look at these 16 different possible futures - and we try to look for agreement amongst them - if you take any one of those projections and we know that they're imperfect but we know that the possible future that we're going to face is more like one of them than the average of all the 16. And we see, when you look any one of the future projections, pretty drastic changes in fire that are pretty rapid.
And so, it forces us to, I think, take climate change and fire a little bit more seriously. It's going to mean that there are going to be some big changes that are going to affect all of the things that we rely on - water supplies, food sources. And we have to learn to live with fire like we've learned to live with earthquakes and floods, and so on. Instead of fighting fire, which is the main way we view fire, we have to learn to accommodate it and coexist with it.
CORNISH: Is there any sense from the models that this trend could be reversed?
MORITZ: Most of the models that we have used here assume a certain emissions scenario. And so, another good lesson from this is that if you look at the lower emissions scenarios you see less changes in the differences in fire activity. So yes, we do have the ability to possibly do something about this, but it means getting a handle on greenhouse gas emissions and taking climate change more seriously.
CORNISH: Well, Max, thank you for explaining your work.
MORITZ: You're very welcome. Thanks for having me.
CORNISH: Max Moritz is on the faculty at the University of California, Berkeley's College of Natural Resources.
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